Many businesses, such as no-appointment hair salons, offer services to customers on a first-come, first-served basis and do not accept appointments. Because of this, customers typically do not know how long of a wait it will be to receive a desired service until arrival at the business location. If the wait is too long, the customer may decide to forego the service altogether. Although the customer can call ahead to learn an estimated wait time, many businesses do not allow a customer to have the customer's name put on the wait list until the customer enters the store. In addition, some businesses have numerous locations situated relatively near each other to which a customer has the option of going. However, a customer cannot practically determine which location will be able provide the desired service the soonest, as this would entail visiting each location or making numerous phone calls to inquire about each location's wait time. In addition, the wait times customers receive are simply guesses by the employees typically based solely on the number of customers currently on the waiting list. Due to variations in the time it takes different employees to perform different services, such guesses are usually grossly inaccurate.